Charles e



(N0 Model.)-

I C. E. SGRIBNER.

SPRING JAGK SWITCH.

No. 489,570. Patented Jan. 10, 1893.

UNITED STATES PATENT OFFICE.

CHARLES E. SCRIBNER, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE WESTERN ELECTRIC COMPANY, OF SAME PLACE.

SPRING-JACK SWITCH.

SPECIFICATION forming part of Letters Patent No. 489,570, dated January 10, 1893.

Application filed December 27, 1880. Renewed February 24, 1890. Serial No. 341,402- (No model.)

T on whom it may concern: each branch of the metallic circuit and a ter- Be it known that I, CHARLES E. SCRIBNER, minal with the necessary contact points. a citizen of the United States, residing at Chi- When a loop plug is inserted in one of the cago, in the county of Cook and State of Illiswitches, the different terminals of the menois, have invented a certain new and useful tallic circuit are connected respectively with Improvement in Spring-Jack Switches, (Case different points of the plug, and hence with No. 121,) of which the following is a full, clear, different strands of the flexible cord, and the concise, and exact description, reference beconnection or terminal of the test wire is ing had to the accompanying drawings, formclosed to the portion of the metallic circuit 10 ing a part of this specification. which was cutoff by the insertion of the plug.

In multiple switch board systems of tele- .My invention consists in two springs, one

phone exchange a different switch or spring of which carries the contact point against jack is provided for each line for each board. which the main lever of the switch normally In large exchanges the wires are bunched torests, the main switch lever having greater I 5 gether in cables and great trouble frequently strength or resiliency than the spring which arises on account of the induction between carries the contact point. These springs of the differentlines. In order to reduce the ineach switch are placed on opposite sides of duction or cross talk, metallic circuits are dethe rubber strip, the contact point projecting sirable, the different limbs or sides of each upward through a hole provided in the rubzo telephone line being placed near together in her strip. WVhen the main lever of the switch the same cable. When metallic circuits are is in its normal position against the contact thus employed all the points of my spring point, the spring carrying the contact point jack switch shown in Patent No. 305,021 of is carried away from the test point of the September 9, 1884., are employed forthe conswitch. On inserting a plug so as to lift the 25 nections of the telephone lines, there being main spring or lever, the spring carryingthe no points or connections for the test wires. I contact point closes again upon the test point, find it necessary, therefore, in metallic circuit the amplitude of its motion being limited by multiple systems, to provide additional points said test contact point so that the point will and connections upon the spring jack switches not be carried as far as the main lever is 30 for the test wires, so that it may be deterliftedby the plug. The ringor metallicsocket 8o mined at one board whether any given line of the spring jack is permanently insulated is in use or connected at any other board. from all the other parts of the switch and is The number of switches and the contactpoints provided with a connection which is carried of each switch being thus necessarily inback of the switch board.

3 5 creased in large exchanges, it becomes of the My invention is illustrated in the accomgreatest importance to construct the switch panying drawings, in whichso that it may occupy the smallest possible Figure 1 is a transverse vertical sectional space or area upon the switch board. view of my spring jack with a loop plug in- My invention herein is designed to provide serted therein. Fig. 2 is a top view showing 40 the necessary contact pieces and connections the main springs of two switches in detail upon the spring jack switch for metallic cirand the connections of themetallic sockets to cuits and forthe test wires, and to arrange the the rear. Fig. 3 is a view from below showseveral parts of the springjacks in such maning the spring carrying contact point and the ner that they will be efficient and strong and test piece with its connection to the rear.

45 occupy as little area as possible upon the Fig. 4 is a front elevation of a section showswitch board. The spring jacks may be built ing the test points below the sockets. up in sections each containing, say, twenty Like parts are indicated by similar letters spring jacks. The main body or frame of each of reference throughout the different figures. section is preferably of hard rubber and each One branch a. of the metallic circuit may 50 spring jack is provided with a terminal for be connected with the main spring I) and [O0 thence normally to contact a which is carried upon spring (I. The other branch 0 is connected with the connection f to the insulated ring or socket. A test piece 9 is provided under each spring jack upon the face of the board and is provided with a connection 9 to the rear, so that the test pieces upon the different boards of any given line may be permanently connected together by the test wire of the line. The spring d is of less strength or resiliency than spring Z) and hence when spring I) rests against contact point 0, spring d will be separated from test piece g. On inserting a plug, however, to lift the spring or lever b from contact 0, spring at closes upon said test piece g as shown in Fig. 1. This connection between the test piece 9 and the portion of branch a, which is cut off on inserting the plug, is necessary in order that the test piece g may have a connection to ground.

The contact 0 and the spring 65 together form a yielding connection for the main lever b and the resiliency or force of the auxiliary spring d being less than that of the main lever or spring I) the yielding contact will be moved away from its stop 9 when the main lever rests upon this connection. When the main lever is lifted the yielding connection will follow the lever a short distance, its movement, however, toward the main lever being limited by the stop g.

As the test circuits proper form another part of my invention l1erein,I have not shown the connections between spring jacks on different multiple switch boards. These circuits are referred to simply for the purpose of showing the utility of my invention.

It is evident that my switch may be used for any purpose to which it may be adapted,

and I do not, therefore, limit my invention to any particular circuits or system of circuits.

Having thus described my invention I claim as new and desire to secure by Letters Patent:-

1. The combination with a spring jack switch of a loop plug inserted therein, the main leverof said switch being lifted by said plug from its normal contact point, a spring carrying said contact point which closes upon a test piece of the switch when the main spring is lifted and the insulated ring or terminal which is closed to the other point of the loop plug, whereby the two line terminals of the switch are connected with different points of the plug and the test piece of the switch connected with the normal contact point of the main spring or lever, substantially as shown and described.

2. The combination in a spring jack switch of the main spring I) and the contact 0 carried upon an auxiliary spring (2 having less force than the main spring and the test piece g accessible at the front of the spring jack with which test piece the springd is adapted to close when the main spring is lifted, substantially as and for the purpose specified.

3. In a spring jack switch, the combination with the main spring or lever, of a yielding contact or connection against which said spring is adjusted to normally press, and a stop for limiting the movement of said yielding contact toward said spring, substantially as and for the purpose specified.

In witness whereof I hereunto subscribe my 75 name this 16th day of November, A. D. 1886.

CHARLES E. SCRIBNER. Witnesses:

GEORGE P. BARTON, WM. M. GILLER. 

